Tube cleaning apparatus



Patented June 20, 1944 VUNITED STATES PATENroFFlcE TUBE CLEANING APPARATUS Donald E. Schott, FlushnggN. Y., assignorv to Thomas C. Wilson, Inc., Long Island City, N. Y., a corporation of New York Application May 14, 1943, Serial No. 487,057'

(c1. 1in- 6) 13 Claims.

Y This invention relates to devices for imparting rotary and rectilinear movements to an element, such as a tool, and is concerned more particularly with a novel device of the type referred to, which is simple-in constuction and highly effective in operation. The new vdevice is useful innumerous applications, but, since it may be employed to especial advantage in association with tube cleaning apparatus, lan embodiment of the invention-suitable for that use will be illustrated and described in detail for purposes of explanation.

In the co-pending 4'application of Schott and Crepeau, Serial No. 485,390, `tiled May 1, 1943, there is disclosed a tubecleaning apparatus which includes a high speed motor, a hollow shaft driven thereby, and a bit mounted at the free end of the shaft. Thebit is 'provided with cutting projections-atits forward end and the surfaces of the bit'opposed to the inner wall of the tube are blunt, so that inthe operation of the apparatus, the bit acts on vthe face of the deposit at right angles to the axis of the tube and performs its function without likelihood of injury to the tube wall. The motor of the apparatus of the application 'has a casing into which fluid for ilushing purposes may be intro-duced to flow out through the hollowl shaft and escape through a discharge opening at the operating end of the bit centrally of the'cutting projections. flushing fluid, which may be compressed air,

continuallyremoves the debris broken free by to'control the hammering action and make it light Y or heavy, as desired. without interfering with or altering the ratel of rotation.

The new device includes a rotary driven member, which is adapted to be driven by amotor of any desired type andincludes a chamber for receivingw auid under pressure. A spindle is connected toJthe chamber for `rotary movementy therewith and has a limitedfreedom of longitudinalumovement relative to theV member.. vThe Thef ment to which the rotary and rectilinear movements are to be impartedand, when the device is employed with tube cleaning apparatus, the member is connected to the motor of the apparatus and the spindle is connected to the shaft on which thebit is mounted. A hammer is mounted on the member for reciprocatory movement relative thereto and the device includes means receiving pressure fluid from the passage and operating to cause the hammer to reciprocate. The pressure fluid also acts on the spindle and normally holds the spindle in an advanced position, but when the spindle is in a retracted position because, for example, of vresistance offered by the deposit, the hammer in its reciprocation acts upon vaportion of the spindle and forces it forward. The hammer reciprocates throughout the operation ofthe device, but acts upon the spindle only when the latter is in retracted position. The "extent to which the spindle is retracted can be determined bythe operator and he can thus control the elfect'of the hammer on the spindle and determine Whether the hammering action is light or heavy.

For a better understanding of the invention, reference may be had to the accompanying drawing in which Fig. 1 is a planview of the apparatus as utilized with a tube cleaning apparatus ofthe construction disclosed in the Schott and Crepeau application above mentioned;

Figs. 2 and 3 are longitudinal sectional views throughv the device-with the parts in dilferent relative positions; and

Fig. 4 is a sectional View on the line 4 4 Fig. 2. s

. The apparatus shown in Fig. 1 of the drawing includesa high speed motor I0, to the shaft II of which is connected the device I2 of the present application. This device is connected through a shaft support I3 to a hollow shaft I4, on the spindle is ,adapted tobeconnected to the elefree end of which is mounted a bit I5. In use, the motor is suspended in any convenient manner and the motor and associated parts can be l end of the shaft is screwed. Within the member is a. passage I9 which receives fluid under pressure through the hollow motor shaft. A spindle 2l! extends into the member so that its inner end closes one end of the passage and is acted on by the pressure uid therein. The spindle is provided with a number of longitudinal grooves 2| in which are seated small rolls 22 and these rolls project out of the grooves with their projecting portions entering similar grooves in a nut 23 threaded on the end of the member. arrangement, the spindle can move lengthwise of the member I8 to a limited extent but is continuously connected to the member I8 for rotation therewith. At its free end, the-spindleis threaded, as indicated at 24, so that this end may enter and be connected to the'shaft support I3, and between its ends, the spindles provided with a flange 25 having an operating surface 26.

The spindle has a passage 21 leading outward from its inner end to radial passages 23, which open through the periphery of the spindle. A similar longitudinal passage 2S leads inward from the outer end of the spindle to `radial passages and passages 21 and 29 are connected by a passage 3I cf reduced diameter. The member I8 is provided with a circumferential chamber 32 to which passagesY 28, 30 are open, when the spindle is in its advanced position, as shown in Fig. 2. In this condition ofthe parts, pressure fluid from passage I3 will flow `through passages 21, 28, chamber 32, and passages 30, 29 to the interior of shaft Support I3, .andthe fluid will then flow through hollow shaft I4 and escape through the centrali discharge opening in the end of bit I5. A small amount of fluid will ralso Vfdow from passage 21 through the small diameter passage 3I into passage 29, regardless. of the position of the spindle. When the spindle is in the retracted position shown in Eig. 3, passages 28, 30 are out of communication with chamber 32, in which event, `fluid will .dow from. passagev I9 into kpassage 21 and thence through the small diameter passage 3l into passage' 2B. The amount of fluid flowing outward to the bit when the spindle is in retracted positionis'con'siderably reduced from that flowing when the spindle is at the advanced position shown in Fig. 2.

Mountedto encircletheA member I8 is a ham-` mer 33, in the rear end Vof which is mounted a bushing 34 held in placebyv a bonnet 35 threaded on the hammer. The interior vof the hammer and the outer surface of member I8 are constructed to define an annular chamber36 at the inner end of the bushing and, when the hammer and member are in proper relative positions, this chamber is Aconnectedl through ports 31 in the member to the passage I9. The hammer and member are also formed to define a second annular charnber 38 which may be connected to passage I9 through ports 3S.- The chamber 38 is formed with an annularlextension' 40, which may connect chamber 38 to exhaust ports 4I formed in the-member.

When the device is in operation, the hammer is continually reciprooated Irelative to member I8 by the pressure fluid supplied to passage I9 and the hammer is without effect on the spindle so long as the latter is in an advanced position. However, as vthe member I8- is moved forward relative to the spindle, such movement brings the flange 25 on the spindle intofthe range of movement ofthehammer and, onthe next forward movement of the hammer, the front end of the latter strikes the flange and. tends to force the With this spindle, the hollow shaft, and the bit forwardly. The force of the blow and the extent of forward movement of the spindle and its associated parts depend on the relative positions of the spindle and member i3, and the operator may thus control the hammering action by manipulation of handle i6 connected to the motor, the shaft of which is connected rigidly to member I8.

The reciprocation of the 'hammer relative to the member is effected as follows. When the parts are in the condition shown in Fig. 2, fluid under pressure flows through ports 31 into chamber 33 and acts on the forward end of bushing 33 which serves as a piston surface. At this time, chamber 33 is shut off from port 39 but is open through chamber 40 to exhaust ports di, so that there is no fluid under pressure in chamber 38 and the fluid is, accordingly, effective to move the hammer to the rear. As the hammer continues to move back, the portion of chamber 33, designated 38a and formed in the inner surface of the hammer, moves-into communication with the outer ends of ports `39 and, at the same time, communication is cut off between chamber v38 and chamber 40. Pressurefluid from passage I9 then flows through ports 39 into cham. ber 38 and acts on the forward wall 42 thereof as a piston surface. This piston surface is of greater area than the area of the end of bushing 3ft and the differential pressures on the two piston faces cause the` hammer to start forward.

In the forward movement of the hammer, the latter ultimately advances to the position shown in Fig. 3, in which ports 39 are cut off from communication with chamber 38 and chamber 38 is in communication with the atmosphere through chamber 40 and ports 4I. Just before the hammer reaches the end of its forward stroke, the bushing 34 closes the ends of ports 31 so that a quantityk of air is trapped in chamber 36. The air so trapped is further compressed during the completion of the forward movement of the hammer and acts as a cushion for the advancing hammer to bring it to rest without shock. When chamber 38 is opened to the atmosphere, the air trapped in chamber 3Ii'v acts on the end of bushing 34 to initiate the rearward movement of the hammer.

The effectiveness of the blow of the hammer on the spindle is determinedby the difference between the areas of the piston face 42 in chamber 38 and ofthe piston face at the forward end of bushing 34. This difference-should be as great as possible in order to increase the effectiveness of the hammer, but if the piston surface on the end of thebushing is too small, the return stroke of the hammer is slowed down and this reduces the number of blows per unit of time and the overall effectiveness of the device. In the present construction, the piston surface on the bushing on which the fluid acts to return the hammer is relatively small, but the disadvantage of such a small piston surface is overcome by the trapping of air in chamber 36. The air so trapped and further compressed during the comy pletion-of the forward movement of the hamis connected for rotary movement with member I8 and the'motor shaft but is free to move longitudinally relative to member I8 to a limited extent, a number of advantages are obtained.

Thus, the impact of the hammer on the spindle does not result rin any shock on the motor shaft and the inertia `of the parts acted on by the hammer is reduced so that the effectiveness of the blow is increased. In addition, the spindle may be moved into or out of range of action of the hammer, as desired. The air in passage I9 ordinarily holds the spindle forwardly out of range of the hammer so that the spindle is rotated and the bit performs its functions Without any hammer action. When sunicient resistance to the forward progress of the bit is encountered, a relative movement of the spindle and member I8 occurs and this causes the flange on the spindle to come-into the range of movement of the hammer with the result that the hammering action is obtained. By manipulation of the motor and member I8, the operator may vary the effect of the hammer on the spindle and thereby cause the bit to strike the deposit with heavy or light blows, as desired, while rotation of the bit continues without interruption or change.

Throughout the operation ofthe device, air from passage I9 flows through the spindle and hollow shaft and escapes centrally of the bit at the cutting end of the latter for scavenging purposes. When the spindle is in the forward position, a substantial volume of air is'supplied to the bit through longitudinal passage 21, radial passages 28, chamber 32, radial passages 30, and longitudinal passage 23, and air also ows directly from passage 21 to passage 29 through the small passage 3|. When the spindle is in retracted position, radial passages 23 and 3B are cut off from chamber 32 and the amount of scavenging air is substantially reduced, since itis limited to the quantity that can flow from passage 21 through small passage 3l to passage 29. Thus, during ordinary cutting with the spindle forward, a substantial volume of scavenging air is provided and little of the air isused for operating the hammer, but when the spindle is forced back by resistance to cutting and the hammer is in action, the greater proportion of the air is used for operating the hammer and the volume of air for scavenging is greatly cut down. Accordingly, the air supplied to the device is used to thebest advantage and its manner of use depends on the manner in which the device is operated.

I claim:

1..In a device for imparting rotary and rectilinear movements to an element, the combination of a rotary driven member having a passage for receiving fluid under pressure, a spindle mounted in the member for rotary movement therewith and having a limited freedom of longitudinal movement relative to the member, and a hammer mounted movably on the member and with the latter defining chambers receiving fluid from the passage and having piston surfaceson which the uid acts to reciprocate the hammer lengthwise of the member, the hammer acting on the spindle, when the latter is in one position relative to the member, tomove the spindle to another position.

2. In a device for imparting rotary and rectilinear movements to an element, the combination of a rotary driven member having a passage for receiving fluid under pressure, a spindle mounted in the member for rotary movement therewith and having a limited freedom of longitudinal movement relative to the member, and a hammer mounted movably on the member and with the latter defining chambers receiving duid from the passage and having piston surfaces on which the fluid-actsto reciprocate the hammer lengthwise of the member, the hammer engaging a part of the spindle, when the latter is in retracted position, to move the spindle outwardly relatively to the member. f

3.In a device for imparting rotary and rectilinear movements toan element, the combination of a rotary driven member having a passage for receiving fluid under pressure, aspindle mounted in the member forrotary movement therewith and having a limited freedom of longitudinal movement relative to'the' member, the spindle having a portion providing-an operating surface, and a hammer mounted movably on the member andwith thel latter defining chambers receiving fluid from the passage and having piston surfaces on which the fluid acts to reciprocate the hammer lengthwise of the member, the hammer engaging theoperating surface of the spindle, when the latter is in retractedposition relative to the member, to move the spindle outwardly relatively to the member.

, 4. In a device for imparting rotary and recti linear movements to van element, the combination of .aY rotary driven member having a passage for receiving huid-under pressure, a spindle mounted in the member for rotary movement therewith and having a limited freedom of longitudinal movement relative to the member, the spindle having a portion providing an operating surface, and a 'hammer mounted movably on the member and with the latter defining chambers receiving fluid from the passage and having piston surfaces on which the uid acts to reciprocate the hammer lengthwise of the member, the operating surface on the spindle lying outside the range of movement of the hammer, when the spindle is in an outer position, but engageable by the hammer when the spindle is in retracted position, the hammer then acting on the spindle to move the latter outwardly. l

'5. In a device for imparting rotary and rectilinear movements to an element, the combination of a rotary driven member having a passage for receiving a fluid under pressure, a spindle mounted in the member and having one end closing the passage, the spindle being connected to the member for rotation therewith and having limited longitudinal movement lengthwise ofthe passage, the spindle having a portion projecting out of the member and adapted for connection of said element thereto, and a hammer mounted for longitudinal movement on the member and with the latter ldefining chambers receiving fluid from the passage and having piston surfaces on which the fluid acts to'reciprocate the hammer, the projecting portion of the 'spindle being engagleable by the hammer, when the spindle is in retracted position, to advance vthe spindle with the hammer. f

6. In a device for imparting rotary and rectilinear movements to an element, the combination of a rotary driven member havin-g a passage for receiving a fluid under pressure, a spindle mounted in the member yand having one end closing Vthe passage, the spindle being connected to the member for rotation therewith and having limited longitudinal movement lengthwise of the passage, the spindle having a .portion projecting out of the member and .adapted for connection of said element thereto, a iiange on the projecting portion of the spindle, and a hammer mounted for longitudinal movement relative to the member and with the latter defining chambers receiving iiuid from the passage and having piston surfaces on which the uid acts to reciprocate the hammer, the hammer engaging the flange, when the spindle is in retracted position, and moving the spindle with it.

7. In a device for imparting rotary and rectilinear movements to an element, the combination of a rotary driven member vhaving a passage for receiving fluid under pressure, a spindle having a portion entering the passage and a portion lying outside the member and yadapted for connection to said element, means for connecting the spindle and member for rotary movement in unison while permitting their relative longitudinal movement, a hammer mounted for longitudinal movement on the member, means operable by the iiuid for reciprocating the hammer, and means on the projecting portion of the spindle engageable by the hammer, when the spindle is in retracted position, to cause'the hammer to advance the spindle.

8. In a device for imparting rotaryv and rectilinear movements to an element, the combination of a rotary driven member, a kspindle connected to the member to berotated thereby and having a limited freedom of movementlongitudinally of the member, the spindle vbeing adapted to be connected to said element, a hammer enclosing the member and mounted thereon for movement lengthwise of the member through a path partially overlapping the path of free movement of the spindle on the member, and means for reciprocating the hammer, the spindle when in retracted position only being engaged by thel hammer to be driven outwardly thereby, the spindle in its outermost position being beyond th range of action of the hammer.

9. In a device for imparting rotary and rectilinear movements to an element, the combination of a rotary driven member, a spindle connected to the member to be rotated thereby and having a limited freedom lol movement longitudinally of the member, the spindle being adapted to be connected to said element, a hammer enclosing the member and mounted thereon for lengthwise movement of the member through a path partially overlapping the path of free movement of the spindle relative to the member, and fluid operated means for reciprocating the hammer, the spindle when in retracted position only being engaged by the hammer to be driven outward thereby, and being beyond the range of action of the hammer when in its outermost position.

10. In a device for imparting rotary and rectilinear movements to an element, the combination of a rotary driven member having a passage for receiving a fluid under pressure, a spindle projecting into the passage and connected to the member for rotary movement therewith while having limited freedomof longitudinal movement relatively to the member, the spindle having a 'passage therethrough which is open to the first passage and of smaller diameter, the iluidunder pressure in the first passage normally maintaining the spindle in outermost position, a hammer mounted on the membenand means actuated by fluid received from the rst passage for reciprocating the hammer, the hammer being operable on the spindle, when the latter is in retracted position, to advance the spindle with it.

11. In a device for imparting rotary and rectilinear movements to an element, the combination of a rotary driven member having a passage for receiving a fluid under pressure, a spindle projecting into the passage and connected to the member for rotary movement therewith while having limited freedom of longitudinal movement relatively to the member, a passage in the inner section of the spindle open to the passage in the member and of smaller diameter than that passage, the spindle passage leading to the periphery of the spindle, a passage in the outer section of the spindle leading from the periphery of the spindle near the end of the inner spindle passage to the outer end of the spindle, a chamber in the member connecting the peripheral ends of the spindle passages only when the spindle is in substantially outermost position, a hammer mounted on the member, and means actuated by the pressure iluid in the passage in the member for reciprocating the hammer lengthwise of the member, the hammer being operable upon the spindle, when the latter is retracted, to advance the spindle with it.

12. In a device for imparting rotary and rectilinear movements to an element, the combination of a rotary driven member having a passage for receiving a fluid under pressure, a spindle adapted to be connected to the element, means for connecting the spindle to the. element to be rotated thereby while permitting the spindle to move longitudinally relatively to the member to a limited extent, a hammer mounted movably on the member, a pair of chambers defined by the hammer and member and including piston surfaces of different area on the hammer, a port in the member connectable to the chamber including the smaller piston surface to the passage, a second port in the member connectable with the second chamber, an exhaust port in the hammer, and a third chamber defined by the member and hammer and connecting the second chamber and the exhaust port when the hammer is in an advanced position, the piston being reciprocated by the action of the pressure uid on the piston surfaces and being operable on the spindle, when the latter is in retracted position, to advance the spindle with it.

13. In a device for imparting rotary and rectilinear movements to an element, the combination of .a rotary driven member, a spindle connected thereto for rotation with the member while free to move longitudinally of the member to a limited extent, a hammer enclosing the member and mounted for movement lengthwise of the member through a path partially overlapping the path of free movement of the spindle relative to the member, the hammer having piston surfaces thereon, and means for supplying fluid under pressure to act on the piston surfaces of the hammer to reciprocate the hammer, the spindle when in retracted position only being engaged and driven outwardly by the hammer, and when in outermost position being beyond the range of action of the hammer.

DONALD E. SCHOTT. 

